FRICTION PLATE HAVING MECHANICALLY CONNECTED FRICTION MATERIAL
A method of forming a friction plate is provided. The method includes force fitting a friction material onto a base to form a mechanical connection between the friction material and the base. A friction plate is also provided. The friction plate includes a base and a friction material force fit onto the base such that a mechanical connection is formed by a shape of the friction material and a shape of the base.
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This claims the benefit to U.S. Provisional Patent Application No. 61/730,147, filed on Nov. 27, 2012, which is hereby incorporated by reference herein.
The present disclosure relates to friction plates. Such friction plates may be included in wet clutch packs for use in transmission shifting clutches and brakes or in wet launch clutches for various types of transmissions.
BACKGROUNDFriction plates for use in a clutch are generally manufactured by bonding friction material, often paper-based, to both sides of a steel core plate using an adhesive, often a phenolic resin which is baked in a press. Grooves for cooling oil may be formed in the friction plate by pressing, grinding, or by leaving material out in positions where grooves are desired.
Forming friction plates by bonding friction material to a steel core plate with adhesive may be expensive. The adhesive may cost as much as the friction material itself and the process for handling the adhesive is very sensitive. The adhesive is also flammable and hazardous and therefore requires special handling. Conditions must be maintained very accurately for each plate or durability and performance problems can occur, such as shudder and delamination, which occurs at the line of adhesive penetration into the friction material, or debonding failures. Using adhesive may also have a negative impact on the clutch environment.
U.S. Pat. No. 4,055,236 describes a brake disc in the form of a metal frame having part-circular apertures in which part-circular pads are inserted and held in place by a dowel. U.S. Pat. No. 7,731,005 describes concentrically arranged friction materials integrally connected to each other.
SUMMARY OF THE INVENTIONAn object of the present invention is to form a friction plate without adhesive bonding Instead, a mechanical connection is created between the friction material and the base.
A method of forming a friction plate is provided. The method includes force fitting a friction material onto a base to form a mechanical connection between the friction material and the base.
A friction plate is also provided. The friction plate includes a base and a friction material force fit onto the base such that a mechanical connection is formed by a shape of the friction material and a shape of the base.
The present invention will be further described in a non-limiting manner on the basis of the drawing of preferred embodiments in which:
After plugs 16 are inside of holes 14, friction plate 10 may be compressed between flat plates to calibrate the thickness and flatness of plugs 16. The compression of plugs 16 causes the friction material of plugs 16 to expand outwardly towards the edges of holes 14, further locking plugs 16 into holes 14. The compression of plugs 16 causes the friction material to be force fit on steel ring 12 such that plugs 16 and steel ring 12 are mechanically connected by a shape of the friction material and a shape of the base. In a preferred embodiment, friction material 16, after the compression, extends axially past steel ring 12 at least at the protrusions such that the friction material can contact adjacent separator plates 400 (
After friction material ring 116 is on steel ring 112 in an interlocking manner, friction material ring 116 may be compressed to form cooling grooves on the surface thereof. The compressing operation recesses portions of friction material ring, such that protrusions, similar to the pattern of plugs 16 shown in
Claims
1. A method of forming a friction plate comprising:
- force fitting a friction material onto a base to form a mechanical connection between the friction material and the base.
2. The method as recited in claim 1 wherein the force fitting includes providing the friction material on the base and compressing the friction material to form the mechanical connection between the friction material and the base
3. The method as recited in claim 2 wherein the base includes holes therein, the providing including providing the friction material in the holes, the compressing causing the friction material to expand outwardly in the holes to form the mechanical connection.
4. The method as recited in claim 2 wherein the base includes teeth on a circumference thereof and the frictional material includes teeth on a circumference thereof, the compressing causing the teeth of the frictional material to interlock with the teeth of the base.
5. The method as recited in claim 1 wherein the base is a ring and the friction material is a ring, the force fitting causing the friction material to interlock with the base.
6. The method as recited in claim 1 wherein the base is metal.
7. A friction plate comprising:
- a base; and
- a friction material force fit onto the base such that a mechanical connection is formed by a shape of the friction material and a shape of the base.
8. The friction plate as recited in claim 7 wherein the base is metal ring.
9. The friction plate as recited in claim 7 wherein the base includes a plurality of holes therein, the friction material being formed by plugs inserted in the holes.
10. The friction plate as recited in claim 7 wherein the base is a ring and the friction material is formed as a ring interlocking with the base.
11. The friction plate as recited in claim 10 wherein the base includes a plurality of teeth on a circumference thereof and the friction material includes a plurality of teeth on a circumference thereof, the teeth of the base interlocking with the teeth of the friction material.
12. The friction plate as recited in claim 7 wherein the friction material is in a compressed state so as to lock the friction material onto the base.
13. The friction plate as recited in claim 7 wherein the friction material applies forces towards the base to lock the friction material onto the base.
14. The friction plate as recited in claim 13 wherein the friction material is paper based on the base is a metal ring.
15. The friction plate as recited in claim 7 wherein the friction material extends axially past the base.
16. A wet-type friction clutch comprising:
- at least one friction plate as recited in claim 7.
Type: Application
Filed: Nov 25, 2013
Publication Date: May 29, 2014
Applicant: Schaeffler Technologies AG & Co. KG (Herzogenaurach)
Inventors: Jeffrey Hemphill (Copley, OH), Patrick Lindemann (Wooster, OH), Rashid Farahati (Copley, OH), Srinath Sistla (Wooster, OH)
Application Number: 14/088,683
International Classification: F16D 13/38 (20060101); B60T 1/06 (20060101);